<?php
/**
 * setup.php - Sets up sessions, connects to databases and so on
 *
 * Normally this is only called by the main config.php file
 * Normally this file does not need to be edited.
 * @author Martin Dougiamas
 * @version $Id: setup.php,v 1.212.2.22 2009/01/06 13:09:13 skodak Exp $
 * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
 * @package moodlecore
 */

////// DOCUMENTATION IN PHPDOC FORMAT FOR MOODLE GLOBALS AND COMMON OBJECT TYPES /////////////
/**
 * $USER is a global instance of a typical $user record.
 *
 * Items found in the user record:
 *  - $USER->emailstop - Does the user want email sent to them?
 *  - $USER->email - The user's email address.
 *  - $USER->id - The unique integer identified of this user in the 'user' table.
 *  - $USER->email - The user's email address.
 *  - $USER->firstname - The user's first name.
 *  - $USER->lastname - The user's last name.
 *  - $USER->username - The user's login username.
 *  - $USER->secret - The user's ?.
 *  - $USER->lang - The user's language choice.
 *
 * @global object(user) $USER
 */
global $USER;
/**
 * This global variable is read in from the 'config' table.
 *
 * Some typical settings in the $CFG global:
 *  - $CFG->wwwroot - Path to moodle index directory in url format.
 *  - $CFG->dataroot - Path to moodle index directory on server's filesystem.
 *  - $CFG->libdir  - Path to moodle's library folder on server's filesystem.
 *
 * @global object(cfg) $CFG
 */
global $CFG;
/**
 * Definition of session type
 * @global object(session) $SESSION
 */
global $SESSION;
/** 
 * Definition of shared memory cache
 */
global $MCACHE;
/**
 * Definition of course type
 * @global object(course) $COURSE
 */
global $COURSE;
/**
 * Definition of db type
 * @global object(db) $db
 */
global $db;
/**
 * $THEME is a global that defines the site theme.
 *
 * Items found in the theme record:
 *  - $THEME->cellheading - Cell colors.
 *  - $THEME->cellheading2 - Alternate cell colors.
 *
 * @global object(theme) $THEME
 */
global $THEME;

/**
 * HTTPSPAGEREQUIRED is a global to define if the page being displayed must run under HTTPS. 
 * 
 * It's primary goal is to allow 100% HTTPS pages when $CFG->loginhttps is enabled. Default to false.
 * It's enabled only by the httpsrequired() function and used in some pages to update some URLs
*/
global $HTTPSPAGEREQUIRED;


/// First try to detect some attacks on older buggy PHP versions
	if (isset($_REQUEST['GLOBALS']) || isset($_COOKIE['GLOBALS']) || isset($_FILES['GLOBALS'])) {
		die('Fatal: Illegal GLOBALS overwrite attempt detected!');
	}


	if (!isset($CFG->wwwroot)) {
		trigger_error('Fatal: $CFG->wwwroot is not configured! Exiting.');
		die;
	}

/// store settings from config.php in array in $CFG - we can use it later to detect problems and overrides
	$CFG->config_php_settings = (array)$CFG;

/// Set httpswwwroot default value (this variable will replace $CFG->wwwroot
/// inside some URLs used in HTTPSPAGEREQUIRED pages.
	$CFG->httpswwwroot = $CFG->wwwroot;

	$CFG->libdir   = $CFG->dirroot .'/lib';

	require_once($CFG->libdir .'/setuplib.php');		// Functions that MUST be loaded first

/// Time to start counting	
	init_performance_info();		
	

/// If there are any errors in the standard libraries we want to know!
	error_reporting(E_ALL);

/// Just say no to link prefetching (Moz prefetching, Google Web Accelerator, others)
/// http://www.google.com/webmasters/faq.html#prefetchblock
	if (!empty($_SERVER['HTTP_X_moz']) && $_SERVER['HTTP_X_moz'] === 'prefetch'){
		header($_SERVER['SERVER_PROTOCOL'] . ' 404 Prefetch Forbidden');		
		trigger_error('Prefetch request forbidden.');
		exit;
	}

/// Connect to the database using adodb

/// Set $CFG->dbfamily global
/// and configure some other specific variables for each db BEFORE attempting the connection
	preconfigure_dbconnection();

	require_once($CFG->libdir .'/adodb/adodb.inc.php'); // Database access functions

	$db = &ADONewConnection($CFG->dbtype);

	// See MDL-6760 for why this is necessary. In Moodle 1.8, once we start using NULLs properly,
	// we probably want to change this value to ''.
	$db->null2null = 'A long random string that will never, ever match something we want to insert into the database, I hope. \'';

	error_reporting(0);  // Hide errors

	if (!isset($CFG->dbpersist) or !empty($CFG->dbpersist)) {	// Use persistent connection (default)
		$dbconnected = $db->PConnect($CFG->dbhost,$CFG->dbuser,$CFG->dbpass,$CFG->dbname);
	} else {													 // Use single connection
		$dbconnected = $db->Connect($CFG->dbhost,$CFG->dbuser,$CFG->dbpass,$CFG->dbname);
	}
	if (! $dbconnected) {
		// In the name of protocol correctness, monitoring and performance
		// profiling, set the appropriate error headers for machine comsumption
		if (isset($_SERVER['SERVER_PROTOCOL'])) { 
			// Avoid it with cron.php. Note that we assume it's HTTP/1.x
			header($_SERVER['SERVER_PROTOCOL'] . ' 503 Service Unavailable');		
		}
		// and then for human consumption...
		echo '<html><body>';
		echo '<table align="center"><tr>';
		echo '<td style="color:#990000; text-align:center; font-size:large; border-width:1px; '.
			 '	border-color:#000000; border-style:solid; border-radius: 20px; border-collapse: collapse; '.
			 '	-moz-border-radius: 20px; padding: 15px">';
		echo '<p>Error: Database connection failed.</p>';
		echo '<p>It is possible that the database is overloaded or otherwise not running properly.</p>';
		echo '<p>The site administrator should also check that the database details have been correctly specified in config.php</p>';
		echo '</td></tr></table>';
		echo '</body></html>';

		error_log('ADODB Error: '.$db->ErrorMsg()); // see MDL-14628

		if (empty($CFG->noemailever) and !empty($CFG->emailconnectionerrorsto)) {
			if (file_exists($CFG->dataroot.'/emailcount')){
				$fp = fopen($CFG->dataroot.'/emailcount', 'r');
				$content = fread($fp, 24);
				fclose($fp);
				if((time() - (int)$content) > 600){
					mail($CFG->emailconnectionerrorsto, 
						'WARNING: Database connection error: '.$CFG->wwwroot, 
						'Connection error: '.$CFG->wwwroot);
					$fp = fopen($CFG->dataroot.'/emailcount', 'w');
					fwrite($fp, time());
				}
			} else {
			   mail($CFG->emailconnectionerrorsto, 
					'WARNING: Database connection error: '.$CFG->wwwroot, 
					'Connection error: '.$CFG->wwwroot);
			   $fp = fopen($CFG->dataroot.'/emailcount', 'w');
			   fwrite($fp, time());
			}
		}
		die;
	}

/// Forcing ASSOC mode for ADOdb (some DBs default to FETCH_BOTH)
	$db->SetFetchMode(ADODB_FETCH_ASSOC);

/// Starting here we have a correct DB conection but me must avoid
/// to execute any DB transaction until "set names" has been executed
/// some lines below!

	error_reporting(E_ALL);	   // Show errors from now on.

	if (!isset($CFG->prefix)) {   // Just in case it isn't defined in config.php
		$CFG->prefix = '';
	}


/// Define admin directory

	if (!isset($CFG->admin)) {   // Just in case it isn't defined in config.php
		$CFG->admin = 'admin';   // This is relative to the wwwroot and dirroot
	}

/// Increase memory limits if possible
	raise_memory_limit('96M');	// We should never NEED this much but just in case...

/// Load up standard libraries

	require_once($CFG->libdir .'/textlib.class.php');   // Functions to handle multibyte strings
	require_once($CFG->libdir .'/weblib.php');		  // Functions for producing HTML
	require_once($CFG->libdir .'/dmllib.php');		  // Functions to handle DB data (DML)
	require_once($CFG->libdir .'/datalib.php');		 // Legacy lib with a big-mix of functions.
	require_once($CFG->libdir .'/accesslib.php');	   // Access control functions
	require_once($CFG->libdir .'/deprecatedlib.php');   // Deprecated functions included for backward compatibility
	require_once($CFG->libdir .'/moodlelib.php');	   // Other general-purpose functions
	require_once($CFG->libdir .'/eventslib.php');	   // Events functions
	require_once($CFG->libdir .'/grouplib.php');		// Groups functions

	//point pear include path to moodles lib/pear so that includes and requires will search there for files before anywhere else
	//the problem is that we need specific version of quickforms and hacked excel files :-(
	ini_set('include_path', $CFG->libdir.'/pear' . PATH_SEPARATOR . ini_get('include_path'));

/// Disable errors for now - needed for installation when debug enabled in config.php
	if (isset($CFG->debug)) {
		$originalconfigdebug = $CFG->debug;
		unset($CFG->debug);
	} else {
		$originalconfigdebug = -1;
	}

/// Set the client/server and connection to utf8
/// and configure some other specific variables for each db
	configure_dbconnection();

/// Load up any configuration from the config table
	$CFG = get_config();

/// Turn on SQL logging if required
	if (!empty($CFG->logsql)) {
		$db->LogSQL();
	}

/// Prevent warnings from roles when upgrading with debug on
	if (isset($CFG->debug)) {
		$originaldatabasedebug = $CFG->debug;
		unset($CFG->debug);
	} else {
		$originaldatabasedebug = -1;
	}


/// For now, only needed under apache (and probably unstable in other contexts)
	if (function_exists('register_shutdown_function')) {
		register_shutdown_function('moodle_request_shutdown');
	}

/// Defining the site
	if ($SITE = get_site()) {
		/**
		 * If $SITE global from {@link get_site()} is set then SITEID to $SITE->id, otherwise set to 1.
		 */
		define('SITEID', $SITE->id);
		/// And the 'default' course
		$COURSE = clone($SITE);   // For now.  This will usually get reset later in require_login() etc.
	} else {
		/**
		 * @ignore
		 */
		define('SITEID', 1);
		/// And the 'default' course
		$COURSE = new object;  // no site created yet
		$COURSE->id = 1;
	}

	// define SYSCONTEXTID in config.php if you want to save some queries (after install or upgrade!)
	if (!defined('SYSCONTEXTID')) {
		get_system_context();
	}

/// Set error reporting back to normal
	if ($originaldatabasedebug == -1) {
		$CFG->debug = DEBUG_MINIMAL;
	} else {
		$CFG->debug = $originaldatabasedebug;
	}
	if ($originalconfigdebug !== -1) {
		$CFG->debug = $originalconfigdebug; 
	}
	unset($originalconfigdebug);
	unset($originaldatabasedebug);
	error_reporting($CFG->debug);


/// find out if PHP cofigured to display warnings
	if (ini_get_bool('display_errors')) {
		define('WARN_DISPLAY_ERRORS_ENABLED', true);
	}
/// If we want to display Moodle errors, then try and set PHP errors to match
	if (!isset($CFG->debugdisplay)) {
		//keep it as is during installation
	} else if (empty($CFG->debugdisplay)) {
		@ini_set('display_errors', '0');
		@ini_set('log_errors', '1');
	} else {
		@ini_set('display_errors', '1');
	}
// Even when users want to see errors in the output,
// some parts of Moodle cannot display them at all.
// (Once we are XHTML strict compliant, debugdisplay
//  _must_ go away).
	if (defined('MOODLE_SANE_OUTPUT')) {
		@ini_set('display_errors', '0');
		@ini_set('log_errors', '1');
	}

/// Shared-Memory cache init -- will set $MCACHE
/// $MCACHE is a global object that offers at least add(), set() and delete()
/// with similar semantics to the memcached PHP API http://php.net/memcache
/// Ensure we define rcache - so we can later check for it
/// with a really fast and unambiguous $CFG->rcache === false
	if (!empty($CFG->cachetype)) {
		if (empty($CFG->rcache)) {
			$CFG->rcache = false;
		} else {
			$CFG->rcache = true;
		}

		// do not try to initialize if cache disabled
		if (!$CFG->rcache) {
			$CFG->cachetype = '';
		}

		if ($CFG->cachetype === 'memcached' && !empty($CFG->memcachedhosts)) {
			if (!init_memcached()) {
				debugging("Error initialising memcached");
				$CFG->cachetype = '';
				$CFG->rcache = false;
			}
		} else if ($CFG->cachetype === 'eaccelerator') {
			if (!init_eaccelerator()) {
				debugging("Error initialising eaccelerator cache");
				$CFG->cachetype = '';
				$CFG->rcache = false;				
			}
		}

	} else { // just make sure it is defined
		$CFG->cachetype = '';
		$CFG->rcache	= false;
	}

/// Set a default enrolment configuration (see bug 1598)
	if (!isset($CFG->enrol)) {
		$CFG->enrol = 'manual';
	}

/// Set default enabled enrolment plugins
	if (!isset($CFG->enrol_plugins_enabled)) {
		$CFG->enrol_plugins_enabled = 'manual';
	}

/// File permissions on created directories in the $CFG->dataroot

	if (empty($CFG->directorypermissions)) {
		$CFG->directorypermissions = 0777;	  // Must be octal (that's why it's here)
	}

/// Calculate and set $CFG->ostype to be used everywhere. Possible values are:
/// - WINDOWS: for any Windows flavour.
/// - UNIX: for the rest
/// Also, $CFG->os can continue being used if more specialization is required
	if (stristr(PHP_OS, 'win') && !stristr(PHP_OS, 'darwin')) {
		$CFG->ostype = 'WINDOWS';
	} else {
		$CFG->ostype = 'UNIX';
	}
	$CFG->os = PHP_OS;

/// Set up default frame target string, based on $CFG->framename
	$CFG->frametarget = frametarget();

/// Setup cache dir for Smarty and others
	if (!file_exists($CFG->dataroot .'/cache')) {
		make_upload_directory('cache');
	}

/// Set up smarty template system
	//require_once($CFG->libdir .'/smarty/Smarty.class.php');
	//$smarty = new Smarty;
	//$smarty->template_dir = $CFG->dirroot .'/templates/'. $CFG->template;
	//if (!file_exists($CFG->dataroot .'/cache/smarty')) {
	//	make_upload_directory('cache/smarty');
	//}
	//$smarty->compile_dir = $CFG->dataroot .'/cache/smarty';

/// Set up session handling
	if(empty($CFG->respectsessionsettings)) {
		if (empty($CFG->dbsessions)) {   /// File-based sessions

			// Some distros disable GC by setting probability to 0
			// overriding the PHP default of 1
			// (gc_probability is divided by gc_divisor, which defaults to 1000)
			if (ini_get('session.gc_probability') == 0) {
				ini_set('session.gc_probability', 1);
			}

			if (!empty($CFG->sessiontimeout)) {
				ini_set('session.gc_maxlifetime', $CFG->sessiontimeout);
			}

			if (!file_exists($CFG->dataroot .'/sessions')) {
				make_upload_directory('sessions');
			}
			ini_set('session.save_path', $CFG->dataroot .'/sessions');

		} else {						 /// Database sessions
			ini_set('session.save_handler', 'user');

			$ADODB_SESSION_DRIVER  = $CFG->dbtype;
			$ADODB_SESSION_CONNECT = $CFG->dbhost;
			$ADODB_SESSION_USER	= $CFG->dbuser;
			$ADODB_SESSION_PWD	 = $CFG->dbpass;
			$ADODB_SESSION_DB	  = $CFG->dbname;
			$ADODB_SESSION_TBL	 = $CFG->prefix.'sessions2';
			if (!empty($CFG->sessiontimeout)) {
				$ADODB_SESS_LIFE   = $CFG->sessiontimeout;
			}

			require_once($CFG->libdir. '/adodb/session/adodb-session2.php');
		}
	}
/// Set sessioncookie and sessioncookiepath variable if it isn't already
	if (!isset($CFG->sessioncookie)) {
		$CFG->sessioncookie = '';
	}
	if (!isset($CFG->sessioncookiedomain)) {
		$CFG->sessioncookiedomain = '';
	}
	if (!isset($CFG->sessioncookiepath)) {
		$CFG->sessioncookiepath = '/';
	}

/// Configure ampersands in URLs

	@ini_set('arg_separator.output', '&amp;');

/// Work around for a PHP bug   see MDL-11237
  
	@ini_set('pcre.backtrack_limit', 20971520);  // 20 MB 

/// Location of standard files

	$CFG->wordlist	= $CFG->libdir .'/wordlist.txt';
	$CFG->javascript  = $CFG->libdir .'/javascript.php';
	$CFG->moddata	 = 'moddata';

// Alas, in some cases we cannot deal with magic_quotes.
	if (defined('MOODLE_SANE_INPUT') && ini_get_bool('magic_quotes_gpc')) {
		mdie("Facilities that require MOODLE_SANE_INPUT "
			 . "cannot work with magic_quotes_gpc. Please disable "
			 . "magic_quotes_gpc.");
	}
/// A hack to get around magic_quotes_gpc being turned off
/// It is strongly recommended to enable "magic_quotes_gpc"!
	if (!ini_get_bool('magic_quotes_gpc') && !defined('MOODLE_SANE_INPUT') ) {
		function addslashes_deep($value) {
			$value = is_array($value) ?
					array_map('addslashes_deep', $value) :
					addslashes($value);
			return $value;
		}
		$_POST = array_map('addslashes_deep', $_POST);
		$_GET = array_map('addslashes_deep', $_GET);
		$_COOKIE = array_map('addslashes_deep', $_COOKIE);
		$_REQUEST = array_map('addslashes_deep', $_REQUEST);
		if (!empty($_SERVER['REQUEST_URI'])) {
			$_SERVER['REQUEST_URI'] = addslashes($_SERVER['REQUEST_URI']);
		}
		if (!empty($_SERVER['QUERY_STRING'])) {
			$_SERVER['QUERY_STRING'] = addslashes($_SERVER['QUERY_STRING']);
		}
		if (!empty($_SERVER['HTTP_REFERER'])) {
			$_SERVER['HTTP_REFERER'] = addslashes($_SERVER['HTTP_REFERER']);
		}
	   if (!empty($_SERVER['PATH_INFO'])) {
			$_SERVER['PATH_INFO'] = addslashes($_SERVER['PATH_INFO']);
		}
		if (!empty($_SERVER['PHP_SELF'])) {
			$_SERVER['PHP_SELF'] = addslashes($_SERVER['PHP_SELF']);
		}
		if (!empty($_SERVER['PATH_TRANSLATED'])) {
			$_SERVER['PATH_TRANSLATED'] = addslashes($_SERVER['PATH_TRANSLATED']);
		}
	}

/// neutralise nasty chars in PHP_SELF
	if (isset($_SERVER['PHP_SELF'])) {
		$phppos = strpos($_SERVER['PHP_SELF'], '.php');
		if ($phppos !== false) {
			$_SERVER['PHP_SELF'] = substr($_SERVER['PHP_SELF'], 0, $phppos+4);
		}
		unset($phppos);
	}

/// The following code can emulate "register globals" if required.
/// This hack is no longer being applied as of Moodle 1.6 unless you really 
/// really want to use it (by defining  $CFG->enableglobalshack = true)

	if (!empty($CFG->enableglobalshack) && !defined('MOODLE_SANE_INPUT')) {
		if (!empty($CFG->detect_unchecked_vars)) {
			global $UNCHECKED_VARS;
			$UNCHECKED_VARS->url = $_SERVER['PHP_SELF'];
			$UNCHECKED_VARS->vars = array();
		}
		if (isset($_GET)) {
			extract($_GET, EXTR_SKIP);	// Skip existing variables, ie CFG
			if (!empty($CFG->detect_unchecked_vars)) {
				foreach ($_GET as $key => $val) {
					$UNCHECKED_VARS->vars[$key]=$val;
				}
			}
		}
		if (isset($_POST)) {
			extract($_POST, EXTR_SKIP);   // Skip existing variables, ie CFG
			if (!empty($CFG->detect_unchecked_vars)) {
				foreach ($_POST as $key => $val) {
					$UNCHECKED_VARS->vars[$key]=$val;
				}
			}
		}
		if (isset($_SERVER)) {
			extract($_SERVER);
		}
	}


/// Load up global environment variables

	if (!isset($CFG->cookiesecure) or strpos($CFG->wwwroot, 'https://') !== 0) {
		$CFG->cookiesecure = false;
	}

	if (!isset($CFG->cookiehttponly)) {
		$CFG->cookiehttponly = false;
	}

	//discard session ID from POST, GET and globals to tighten security,
	//this session fixation prevention can not be used in cookieless mode
	if (empty($CFG->usesid) && !defined('MOODLE_SANE_INPUT')) {
		unset(${'MoodleSession'.$CFG->sessioncookie});
		unset($_GET['MoodleSession'.$CFG->sessioncookie]);
		unset($_POST['MoodleSession'.$CFG->sessioncookie]);
	}
	//compatibility hack for Moodle Cron, cookies not deleted, but set to "deleted" - should not be needed with $nomoodlecookie in cron.php now 
	if (!empty($_COOKIE['MoodleSession'.$CFG->sessioncookie]) && $_COOKIE['MoodleSession'.$CFG->sessioncookie] == "deleted") {
		unset($_COOKIE['MoodleSession'.$CFG->sessioncookie]);
	}
	if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] == "deleted") {
		unset($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie]);
	}
	if (!empty($CFG->usesid) && empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
		require_once("$CFG->dirroot/lib/cookieless.php");
		sid_start_ob();
	}

	if (empty($nomoodlecookie)) {
		session_name('MoodleSession'.$CFG->sessioncookie);
		if (check_php_version('5.2.0')) {
			session_set_cookie_params(0, $CFG->sessioncookiepath, $CFG->sessioncookiedomain, $CFG->cookiesecure, $CFG->cookiehttponly);
		} else {
			session_set_cookie_params(0, $CFG->sessioncookiepath, $CFG->sessioncookiedomain, $CFG->cookiesecure);
		}
		@session_start();
		if (! isset($_SESSION['SESSION'])) {
			$_SESSION['SESSION'] = new object;
			$_SESSION['SESSION']->session_test = random_string(10);
			if (!empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
				$_SESSION['SESSION']->has_timed_out = true;
			}
			if (check_php_version('5.2.0')) {
				setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, $CFG->sessioncookiedomain, $CFG->cookiesecure, $CFG->cookiehttponly);
			} else {
				setcookie('MoodleSessionTest'.$CFG->sessioncookie, $_SESSION['SESSION']->session_test, 0, $CFG->sessioncookiepath, $CFG->sessioncookiedomain, $CFG->cookiesecure);
			}
			$_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] = $_SESSION['SESSION']->session_test;
		}
		if (! isset($_SESSION['USER']))	{
			$_SESSION['USER']	= new object;
		}

		$SESSION = &$_SESSION['SESSION'];   // Makes them easier to reference
		$USER	= &$_SESSION['USER'];
		if (!isset($USER->id)) {
			$USER->id = 0; // to enable proper function of $CFG->notloggedinroleid hack
		}
	}
	else {
		$SESSION  = NULL;
		$USER	 = new object();
		$USER->id = 0; // user not logged in when session disabled
		if (isset($CFG->mnet_localhost_id)) {
			$USER->mnethostid = $CFG->mnet_localhost_id;
		}
	}

	if (defined('FULLME')) {	 // Usually in command-line scripts like admin/cron.php
		$FULLME = FULLME;
		$ME = FULLME;
	} else {
		$FULLME = qualified_me();
		$ME = strip_querystring($FULLME);
	}

/// In VERY rare cases old PHP server bugs (it has been found on PHP 4.1.2 running
/// as a CGI under IIS on Windows) may require that you uncomment the following:
//  session_register("USER");
//  session_register("SESSION");



/// Load up theme variables (colours etc)

	if (!isset($CFG->themedir)) {
		$CFG->themedir = $CFG->dirroot.'/theme';
		$CFG->themewww = $CFG->wwwroot.'/theme';
	}
	$CFG->httpsthemewww = $CFG->themewww; 

	if (isset($_GET['theme'])) {
		if ($CFG->allowthemechangeonurl || confirm_sesskey()) {
			$themename = clean_param($_GET['theme'], PARAM_SAFEDIR);
			if (($themename != '') and file_exists($CFG->themedir.'/'.$themename)) {
				$SESSION->theme = $themename;
			}
			unset($themename);
		}
	}

	if (!isset($CFG->theme)) {
		$CFG->theme = 'standardwhite';
	}

/// now do a session test to prevent random user switching - observed on some PHP/Apache combinations,
/// disable checks when working in cookieless mode
	if (empty($CFG->usesid) || !empty($_COOKIE['MoodleSession'.$CFG->sessioncookie])) {
		if ($SESSION != NULL) {
			if (empty($_COOKIE['MoodleSessionTest'.$CFG->sessioncookie])) {
				report_session_error();
			} else if (isset($SESSION->session_test) && $_COOKIE['MoodleSessionTest'.$CFG->sessioncookie] != $SESSION->session_test) {
				report_session_error();
			}
		}
	}


/// Set language/locale of printed times.  If user has chosen a language that
/// that is different from the site language, then use the locale specified
/// in the language file.  Otherwise, if the admin hasn't specified a locale
/// then use the one from the default language.  Otherwise (and this is the
/// majority of cases), use the stored locale specified by admin.
	if ($SESSION !== NULL && isset($_GET['lang']) && ($lang = clean_param($_GET['lang'], PARAM_SAFEDIR))) {
		if (file_exists($CFG->dataroot .'/lang/'. $lang) or file_exists($CFG->dirroot .'/lang/'. $lang)) {
			$SESSION->lang = $lang;
		} else if (file_exists($CFG->dataroot.'/lang/'.$lang.'_utf8') or 
				   file_exists($CFG->dirroot .'/lang/'.$lang.'_utf8')) {
			$SESSION->lang = $lang.'_utf8';
		}
	}

	setup_lang_from_browser();

	unset($lang);

	if (empty($CFG->lang)) {
		if (empty($SESSION->lang)) {
			$CFG->lang = 'en_utf8';
		} else {
			$CFG->lang = $SESSION->lang;
		}
	}
	
	// set default locale and themes - might be changed again later from require_login()
	course_setup();

	if (!empty($CFG->opentogoogle)) {
		if (empty($USER->id)) {  // Ignore anyone logged in
			if (!empty($_SERVER['HTTP_USER_AGENT'])) {
				if (strpos($_SERVER['HTTP_USER_AGENT'], 'Googlebot') !== false ) {
					$USER = guest_user();
				} else if (strpos($_SERVER['HTTP_USER_AGENT'], 'google.com') !== false ) { // Google
					$USER = guest_user();
				} else if (strpos($_SERVER['HTTP_USER_AGENT'], 'Yahoo! Slurp') !== false ) {  // Yahoo
					$USER = guest_user();
				} else if (strpos($_SERVER['HTTP_USER_AGENT'], '[ZSEBOT]') !== false ) {  // Zoomspider
					$USER = guest_user();
				} else if (strpos($_SERVER['HTTP_USER_AGENT'], 'MSNBOT') !== false ) {  // MSN Search
					$USER = guest_user();
				}
			}
			if (!empty($CFG->guestloginbutton) && empty($USER) && !empty($_SERVER['HTTP_REFERER'])) {
				if (strpos($_SERVER['HTTP_REFERER'], 'google') !== false ) {
					$USER = guest_user();
				} else if (strpos($_SERVER['HTTP_REFERER'], 'altavista') !== false ) {
					$USER = guest_user();
				}
			}
			if (!empty($USER)) {
				load_all_capabilities();
			}
		}
	}

	if (!empty($CFG->guestloginbutton)) {
		if ($CFG->theme == 'standard' or $CFG->theme == 'standardwhite') {	// Temporary measure to help with XHTML validation
			if (isset($_SERVER['HTTP_USER_AGENT']) and empty($_SESSION['USER']->id)) {	  // Allow W3CValidator in as user called w3cvalidator (or guest)
				if ((strpos($_SERVER['HTTP_USER_AGENT'], 'W3C_Validator') !== false) or
					(strpos($_SERVER['HTTP_USER_AGENT'], 'Cynthia') !== false )) {
					if ($USER = get_complete_user_data("username", "w3cvalidator")) {
						$USER->ignoresesskey = true;
					} else {
						$USER = guest_user();
					}
				}
			}
		}
	}

/// Apache log intergration. In apache conf file one can use ${MOODULEUSER}n in
/// LogFormat to get the current logged in username in moodle.
	if ($USER && function_exists('apache_note')
		&& !empty($CFG->apacheloguser) && isset($USER->username)) {
		$apachelog_userid = $USER->id;
		$apachelog_username = clean_filename($USER->username);
		$apachelog_name = '';
		if (isset($USER->firstname)) {
			// We can assume both will be set
			// - even if to empty.
			$apachelog_name = clean_filename($USER->firstname . " " .
											 $USER->lastname);
		}
		if (isset($USER->realuser)) {
			if ($realuser = get_record('user', 'id', $USER->realuser)) {
				$apachelog_username = clean_filename($realuser->username." as ".$apachelog_username);
				$apachelog_name = clean_filename($realuser->firstname." ".$realuser->lastname ." as ".$apachelog_name);
				$apachelog_userid = clean_filename($realuser->id." as ".$apachelog_userid);
			}
		}
		switch ($CFG->apacheloguser) {
			case 3:
				$logname = $apachelog_username;
				break;
			case 2:
				$logname = $apachelog_name;
				break;
			case 1:
			default:
				$logname = $apachelog_userid;
				break;
		}
		apache_note('MOODLEUSER', $logname);
	}

/// Adjust ALLOWED_TAGS
	adjust_allowed_tags();


/// Use a custom script replacement if one exists
	if (!empty($CFG->customscripts)) {
		if (($customscript = custom_script_path()) !== false) {
			require ($customscript);
		}
	}

/// note: we can not block non utf-8 installatrions here, because empty mysql database
/// might be converted to utf-8 in admin/index.php during installation
?>
